The origional equipment one turned off when the ignition turned it off and it was driving me crazy that every time I stoped my GPS would turn off and the laptop adapter would not charge. Here are some pics of what I have I did it over and over again trying to figure out what the deal was. Locate the fuse box - You first need to test the fuse and relay. Have another person push the horn button to test the reading. For '62 and laters, a quick voltage check, is to read voltage between the steering wheel nut and and ground.
How to Fix a Car Horn
Purchase your universal horn button kit.
How to wire a push button horn? 2002 Lancer
Cos apparently the horn is always grounded. Anyone who has a '60 or '61 Beetle and has had to scare up parts for the upper steering column knows just how hard these parts are to find. The ground wire came up the center of the shaft like before, but now the wire from the horn had to come directly to the bearing's outer race.